The purpose of this research is to evaluate an already funded and ongoing intervention to prevent early childhood caries (ECC) in children of low-income families. The intervention began in 10 North Carolina counties in Jan 2000. Pediatricians and nurses are providing preventive dental services, including screening and fluoride varnish applications for infants and toddlers up to 36 months of age, and health education for their primary caregivers. Community coordinators help ensure the fist visit at 9 months of age and at six-month intervals thereafter. The quasi-experimental design will use information from 10 matched counties for comparison. The evaluation consists of three separate studies designed to determine the impact of the intervention on ECC outcomes. In the first study, short-term effectiveness of the intervention will be determined by comparing the prevalence and severity of noncavitated and cavitated carious lesions in 900 3-year-olds, who began the intervention at 9 months of age, with children from the control group. Historical controls from the intervention and comparison counties will account for secular trends in ECC. An interview of caregivers will provide control variables and secondary outcomes, including knowledge, behaviors and quality of life. The second study will determine carryover effects of the intervention on ECC in children 5 years of age, two years after their participation in the intervention ends. Its justification is the need to know if results from early, medical-based interventions continue after children are no longer eligible and before they enroll in school-based preventive dentistry programs. Caries increments derived from public health surveillance of kindergarten students, which includes 95 percent of the 8,000 students in the 20 study counties, will be compared for intervention and control children who were observed in the first study, as well as concurrent controls and historical controls from 4 years before. Interactions between the medical-based interventions and preventive services provided by dentists will be tested using Medicaid and CHIP dental claims. The third study will determine the effects of the ECC interventions for 1- and 2- year-olds on cumulative caries-related (CR) treatment and costs of dental services provided by the Medicaid and CHIP programs through 3 and 4 years of age. The likelihood of hospital use will be analyzed separately from total CR treatment and costs because of its expense. Most analyses will focus on whether net intervention costs (community outreach and provider reimbursements) are offset by reductions in CR treatment costs. We will do a limited assessment of the cost pe oral health- related quality of life.